Blender Git Loki

Cycles: Move tiled path tracer work to own class

The goal is to abstract things a bit and make it possible to tap
more CPU-friendly scheduler to the path tracer.

No functional changes are expecting.

Cycles: Implement special path trace work for CPU

Uses tbb's parallel_for to do pixel partitioning, avoiding overhead
of per-pixel atomic.

Brings render time of bmw27 from 2:19 to 2:10 (2.92 renders in 2:01).

Cycles: Schedule more samples to path trace work

The new scheduling goes as following:

- Render 1 sample, give visual feedback, and see how long it takes to
render a sample.

- After that schedule as many samples as needed to not have more frequent
updates then once a second.

Currently there are no measurable difference, but it will become more
visible once we'll be scheduling more than one sample to GPU.

Cycles: Remove hardcoded tile size

Is not needed since recent fixes from Brecht.

Cycles: Reduce overhead in CPU scheduler

Do samples loop outside of tbb's parallel_for range.
Gives about 2% speedup.

remove remaining derived tree references from MOD_nodes.cc

Sculpt IPMask: Tweak default filter sensitivity

Sculp IPMask: Property to enable/disable step interpolation

Cleanup: Clang format

Sculpt IPMask: Implement restoring and cancelling the filter

Merge branch 'master' into sculpt-dev

Cleanup commented lines

Fix error when exporting several objects

The matrix was wrong

Change to use Vector in object list

Fix after merge

Merge branch 'master' into temp-derived-node-tree-refactor

cleanup naming

remove unused function

cleanup context

cleanup